This invention relates to optical and magnetic disk memory devices, which can include self-validating data encryption hardware and software. The invention is more particularly concerned with a drive module in which the encryption keys are stored in the drive module, and which defeat attempts to compromise the keys or the protected data. Disk-type memory devices can be of any of several types, for example, write-once, and read-only thereafter, an example being a foil sandwich disk, into which bits are recorded by laser; and read/write as desired, either magneto/optic or erasable optical media. As the media are intended for more-or-less permanent storage, these are referred to as write-once, read-many-times optical disks.
There are many applications for encryption/decryption disk drives, including information security and electronic notarization, to name but two. There are a number of practical applications for such systems, including notarization of electronic documents, protection and authentication of legal records, government records, and academic records. For example, a company""s personnel records can be electronically stored, including personal data, performance information, and work evaluations, all of which are sensitive and need to be protected from inspection or use by unauthorized persons. It is also required to be able to authenticate these records, as important hiring, promotion, and pay decisions need to be based on them. However, to date disk drives and similar storage media had to be accompanied with encryption key information, and the data could not be completely protected from experienced xe2x80x9chackers.xe2x80x9d
One attempt to provide data encryption is described in Kittirutsunetorn U.S. Pat. No. 5,081,675, in which a data storage device has its address space divided into data segments, and a programmable address scrambling device is employed, and where a prescribed address sequence is stored in another memory device. This system was created for internal computer architectures rather than for specific disk drives. The appropriate one of several scrambling keys has to be supplied to the programmable address scrambling device in order to retrieve a particular decrypted data word. The Kittirutsunetorn arrangement employs a single integrated circuit and requires random access memory units, or RAMUs, which are critical to the address and data scrambling systems. Address and text data are randomly scrambled by a Programmable Address Scrambling Device, or PASD, and these data are randomly stored, and accessed in memory. The Kittirutsunetom system is interposed between the address port of the data storing device and the data system address buss, scrambles data, and employs completely different hardware and software to accomplish that process. The system microprocessor, system ROM, DRAM, hard drive, address busses and data busses are required for support of the address and data scrambling system. This system does not work satisfactorily for the applications mentioned above, as it scrambles, rather than transforms, the system address and or text data. Also, the Kittirutsunetom system does not locate the microprocessor, ROM keys, ROM firmware, or DRAM registers for encryption and decryption within a sealed and guarded disk or other drive, and provides no real protection from access to the inside of the system, as the hardware and firmware are not all located within the disk drive. Also, there is no means for automatically erasing or deleting encryption key codes in the event an unauthorized person accesses the interior of the disk drive assembly.
Accordingly, it is an object of the present invention to provide circuitry or hardware for protecting stored data that avoids the drawbacks of the prior art.
It is another object to provide a disk storage system in which encryption and decryption keys are stored in a circuit element separate from the data storage disk, and which defeats hacking or access by unauthorized persons.
It is a further object to provide an optical or magnetic-optical encryption/decryption system that is contained in a housing that encloses all the required circuit modules so that the system is self-contained.
In accordance with an aspect of the present invention, an optical encryption/decryption disk drive arrangement has a write-once, read-many-times optical drive of the type that has a recordable optical disk with an address region of track and sector addresses and a region of data tracks adapted for storing encrypted data. The drive has one or more read/write heads and a positioning servo for positioning the read/write head(s) relative to the disk. There is a motor for rotating the disk. An encoded data buffer is coupled to the read/write head and an encryption-decryption module is coupled to this buffer for encrypting data to be stored in the data tracks and addresses to be stored in the address region; and also for decrypting data and addresses read from the buffer. An erasable memory device is coupled to the encryption-decryption module and stores encryption keys for encrypting the data and addresses that are transferred to the encrypted data buffer. The encryption keys are also used for decrypting the data and addresses transferred from the encrypted data buffer. A data buss includes decrypted data input and output paths and is coupled to the encryption-decryption module, so that the data buss conveys decrypted data to and from further processing modules, i.e., processing hardware within the remaining parts of the associated computer. A housing contains the drive, the encrypted data buffer, the encryption-decryption module, the data buss, and the erasable memory device; and there is one or more protective device for disabling the drive motor and positioning servo and for erasing the encryption keys stored in said erasable memory device in the event of an unauthorized access into the housing. A data register or equivalent device can be connected with the data buss as an unauthorized-attempt memory register for counting unauthorized attempts to access the stored data.
According to another aspect of this invention, a magnetic optical dual disk drive arrangement has an optical drive and a separate magnetic drive, such as a hard disk drive. The optical drive can be a write-only, read-many-times CD ROM drive of the type in which a recordable optical disk has data tracks adapted for storing encrypted data, and tracks for storing encrypted track and sector data. The drive has one or more optical read/write heads, a positioning servo for positioning the optical heads, and a motor for rotating the optical disk. The magnetic disk drive includes a magnetic storage disk, one or more magnetic read/write heads, a positioning mechanism for positioning the magnetic head, and a motor for rotating the magnetic disk. A data encrypting and formatting module is coupled to the optical head for encrypting data to be written onto the optical disk and decrypting data picked up by the optical head. This module is also coupled to the magnetic head for encrypting data to be recorded by the magnetic head. A data buss coupled to the data encryption and formatting module conveys decrypted data to and from further processing modules, e.g., the processor of the associated computer. An erasable memory device is coupled to the data encryption and formatting module and is adapted for storing encryption keys for encrypting and decrypting data and format information stored on the optical and magnetic disks. A drive housing contains the optical and magnetic drives, the data encryption and formatting module, and the erasable memory device, and a protective mechanism automatically erases the encryption keys stored in the erasable memory device in the event of an unauthorized opening or accessing the drive housing. In a variation of this arrangement, a microprocessor can be coupled to the formatting buffer and to the encrypt/decrypt module of the data formatting buffer, and can be configured for subtractive data filtering or for additive data filtering.
The above and many other objects, features, and advantages of this invention will become apparent from the ensuing description of selected preferred embodiments, the description being considered in connection with the accompanying Drawing.